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authorIlya Maximets <i.maximets@samsung.com>2019-07-04 16:25:03 +0200
committerDaniel Borkmann <daniel@iogearbox.net>2019-07-12 14:54:57 +0200
commit675716400da6f15b9d3db04ef74ee74ca9a00af3 (patch)
treebe8b1b96c494923785d8a8de31cb84e4d0e27d49 /net/xdp/xsk.c
parentlibbpf: fix ptr to u64 conversion warning on 32-bit platforms (diff)
downloadlinux-675716400da6f15b9d3db04ef74ee74ca9a00af3.tar.xz
linux-675716400da6f15b9d3db04ef74ee74ca9a00af3.zip
xdp: fix possible cq entry leak
Completion queue address reservation could not be undone. In case of bad 'queue_id' or skb allocation failure, reserved entry will be leaked reducing the total capacity of completion queue. Fix that by moving reservation to the point where failure is not possible. Additionally, 'queue_id' checking moved out from the loop since there is no point to check it there. Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Tested-by: William Tu <u9012063@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/xdp/xsk.c')
-rw-r--r--net/xdp/xsk.c11
1 files changed, 4 insertions, 7 deletions
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index d4d6f10aa936..b994c32a664a 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -240,6 +240,9 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
mutex_lock(&xs->mutex);
+ if (xs->queue_id >= xs->dev->real_num_tx_queues)
+ goto out;
+
while (xskq_peek_desc(xs->tx, &desc)) {
char *buffer;
u64 addr;
@@ -250,12 +253,6 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
goto out;
}
- if (xskq_reserve_addr(xs->umem->cq))
- goto out;
-
- if (xs->queue_id >= xs->dev->real_num_tx_queues)
- goto out;
-
len = desc.len;
skb = sock_alloc_send_skb(sk, len, 1, &err);
if (unlikely(!skb)) {
@@ -267,7 +264,7 @@ static int xsk_generic_xmit(struct sock *sk, struct msghdr *m,
addr = desc.addr;
buffer = xdp_umem_get_data(xs->umem, addr);
err = skb_store_bits(skb, 0, buffer, len);
- if (unlikely(err)) {
+ if (unlikely(err) || xskq_reserve_addr(xs->umem->cq)) {
kfree_skb(skb);
goto out;
}